Steam-regulator for turbines.



W. PAPE. STEAM REGULATOR FOR TUHBINES.

APPLICATION FILED JAN.21,1913.

Member;

n im L e M h a V Ma R STATES PA, ET OFFTQE.

WILHELM PAPE, OF CHARLOTTENBURG, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Jan.,27,1914.

Application filed January 21,1913. Serial No. 743,335.

To all whom it may concern:

:Be it known that I, \VILHELM .PAPE, a subject of the King of Prussia, residing at- Charlottenburg, Germany, have invented certain new and useful Improvements in Steam-Regulators for Turbines, of which the following is a specification.

This invention relates to tapped turbines, in which a port-ion of the motive fluid is led ott to a heating or other industrial system after giving up a portion of its energy in the high pressure stage or stages of the machine. In such turbines, the most advantageous condition as regards steam consumption is attained if the cross-sectional areas of the bucket spaces for the low pressure part of the machine are calculated for full load operation. Now when such a turbine is under full load and the heating orother industrial system is taking very little steam, or is wholly shut 03, then the overflow valve between the extraction chamber and the low pressure part of the turbine will stand entirely open, so that the low pressure bucket wheels are getting motive fluid at the same pressure as prevails in the extraction chamher.

It is desirable to maintain the pressure in the heatingsystem at a constant figure, and from this condition it follows that. when the overflow valve is wide open only a certain amount of steam will flow to the low pressure wheels. and thus theenergy delivered I by the low pressure end does not. vary. Now

in case of an overload on the turbine there is no way to carry it unless the high pressure admission valve .is opened wider to sup ply a greater quantity of motive fluid, and this will increase the pressure inUthe .low pressure end, but at the same time it will increase the pressure in the extraction chamber, and therefore the amount of steam pass ing to the heating system, which is undesirable.

The present invention aims to make it possible to carry an overload quite independently of the amount of steam extracted by the heating system.

In the accompanying drawing Figure 1 shows diagrammatically a longitudinal section of a tapped turbine embodying my invention, and Fig. 2 shows a modification.

High pressure steam is admitted at 1 to the high pressure bucket wheel 2, from which it passes into the extra'ction'chamher l I? exposed-on its upper side to the pressure 119 .3 from which it, can be drawnofl by the conduit 4 to supply a heating or other industrial system. An automatically opening main'overflow valve 5 responsive to pressure changes permits the surplus steam, it any, to pass to the low pressure portion of the turbine, where, it acts upon the groups of bucket wheels 6, 7. It Willbenoted that wheel Qforms the high pressure element, wheels 6 what may be termed the intermediatepressure element and wheels/Z the low pressure element.

In working with a. certain amount of steam passing to the heating system,-the turbine may become loaded to such an extent that the valve 5 will be wide open, and thus the maximum amount of steam will pass to the low pressure end of the machine. In order, therefore, to enable the machine to carry an overload under these -circumstances, without increasing the amount of steam passing to the heating system, an auxiliary overflow valve 8 is provided, responsive directly. or indirectly to the increase in steam pressure in the extraction chamber, and arranged to admit steam from said chamber to a later stage of the low pressure portion of the turbine; say to the group of bucket wheels 7, where the bucket spaces are. larger and hence can pass more steam. This produces a greater flow of motive fluid through the turbine, without influencing the amount passing off to the heating system, and because of this increased flow the power furnished by the turbine is correspondingly increased. Although the last group of wheels 7 are thus subjected to a higher pressure than when the valve 8 was closed, yet

the. available power is not entirely in accordance with this increased pressure, because the first group 6 1s Stll)]8Ct8(;l to more or less back pressure. The steam will divide between the two groups in proportion to the resistance of the passages of the first three groups of wheels and that of the pipe leading to the valve 8 and the amount of open ing of the latter.

The valve 5 is preferably operated by a motor comprising a piston 9 working in a cylinder 10 and connected to the stem of the valve. A pilot valve 11 controls the admission and exhaust of motive liquid for said motor and is itself actuated by a pressure responsive device, such as a movable abutment connected to the stem of the valve 5 to fuseiion es s iollow ip device.

Any suitable means may be adopted causing the opening the valve 8 when the speed governor admits increased me amount of steam to the machine. In Fig. 1 there is shown amotor 16 similar totlie one wh ch operates the valve 5 and controlled by the pressure in ilie extraction chamber through the pipe 1'4" and pressure responsive device 18. This device is adjusted to yield to a higher pressure than device 12. The re sell: is that the valve 5 will be entirely opcne l before the device 18 will open the by pass valve 8. In the modificssion shown in Fig. 2 the icy-pass valve 8 is siiangecl as a slide valve upon the stem of the valve 5; that is "so say, the valve is loose upon said. stem and does not open until the collar 19 on said stem strikes is. This action does not take piece until the valve 5 is wide 013811 in accordance with the pyovisions of the patent statutes, 1 have described the principle ofoperetion of my invention, together with the apparatus vvl cli I now consider to represent the leest embodiment thereof; out ll desire to have it understood thei the was shown is onlv illustrative, and that the invention can be earlier} out by other means. What 1 claim as new and desire to secure by Letters of the United States is l. The combination with e tsppell turbine having a main overflow valve for admitting steam to the low pressure end of the machine, of an auxiliary overflow valve for eel Knitting steam from the extraction cliembei directly to a lower stage oi the low pressure end in Gl' llfii to evoicl disturbing the garessure in. the heating system when an overload comes on with illfill'lalil overflow valve Wide ope-i1.

2. The combination. with a tapped turbine having e meiii overflow valve for aclmittiiig steam so the lov-r pressure seal of the mecl'iine, of an auxiliary overfiov' valve responsive to pressure in the extraction chamber snll'opefsting -to admit steam from ssicl chamber to s lower stage of the low pressure eniil lien ails-normal amount of steam admitted to seicl clmiiioei" by reason, of an overload on the turbine.

3; The combination with a tapped turbine having a main overflow valve for admitting steam to the low 13Z'6SSLll6-8Ild of the men and an auxiliary overflow valve for p mg the sseeiil ero'uncl a portion of the low pressure Wheels, said letter valve opening only after the main overflow valve has become Wide open.

The combination with a tappe surbine having a main overflow valve for admitting steam to the low pressure end of the meeliine, auxiliary overflow valve for bypassing the steam. around a portion of the low pressure Wheels sod means responsive to pressure changes in the extraction fillilfib oer for actuating valves in succession.

5. The combination with s tapped turloine having a main overflow valve for admitting steam to the low pi'essuve end of said turreiii'e, euxili i; W valve for loypessing the sieam around. a govt-ion of the low plfiESLlifE wheels, e motor for operating each valwe pilot valve for said motor, and a movable {abutment eoiineotecl to said pilot exposed to the iiuicl pressure in thee ion clisiilioeir.

in wliereoi l have hereunto sei my nsiicl {-1115 51st slay of @ecember i912.

WU PAIFE.

Witnesses HENRY Fries-Wee l OLDEMAR .5. issues. 

